Abstract: An example system for maintaining the shape of a circuit board includes metal balls that are configured not to collapse in whole or part in response to a force below a predefined force and a temperature below a predefined temperature. The metal balls are configured to support a substrate and are part of electrical connections between the substrate and a circuit board. The system includes a fixture configured to apply force to the substrate while the substrate is subjected to the temperature. The fixture is configured to distribute the force across a surface of the substrate that is not in contact with the metal balls such that the force applied by the fixture and the support of the substrate by the metal balls maintains a shape of the substrate at the temperature.